arXiv subjects

Hsiao-Chih Huang

Publications and source records attributed to Hsiao-Chih Huang.

7 recordsLinked to original sources

arXiv2026

Structural Resilience of Space-Time Wave Packets to Volumetric Scattering

Optical space-time wave packets (STWPs) can be engineered to sustain tight transverse confinement over long distances. However, whether the requisite precise spatiotemporal correlations underlying this behavior survive volumetric scattering remains unclear. Here, we experimentally demonstrate that STWP light sheets with transverse thicknesses of 11 and 22 microns largely retain their prescribed spatiotemporal structure after transmission through 10 mm thick scattering phantoms (scattering coefficient = 0.84 per mm). Moreover, compared with size-matched Gaussian beams, STWPs exhibit greater preservation of their initial spectral intensity distribution across the prescribed space-time domain following scattering. Additionally, the transmitted STWPs remain tightly confined and preserve on-axis intensity decay rates similar to those of their unscattered counterparts. As the scattering conditions span biologically relevant regimes, the structural and propagation resilience of STWPs to scattering highlights their potential for extended-depth 3D biomedical microscopy.

physics.optics↗

arXiv2026

Arithmetic with spatiotemporal optical vortex of integer and fractional topological charges

Spatiotemporal optical vortices carry transverse orbital angular momentum (t-OAM), which give rise to spatiotemporal topological charge (ST-TC). To unleash the full potential of t-OAM in expanding the capacity of communication and computing, we demonstrate the first optical information-processing pipeline capable of performing addition and subtraction on ST-TC values, regardless of whether they are integer or fractional. Additionally, we established a readout method for those mathematical operations through imaging spectral analysis, providing a robust optical basis toward arithmetic operations and verification. These new capabilities mark crucial advancements toward full arithmetic operations on the ST-TC of light for bosonic state computation and information processing.

physics.optics↗

arXiv2025

Transverse orbital angular momentum and polarization entangled spatiotemporal structured light

Intra-system entanglement occurs between non-separable modes within the same system. For optical systems, the various degrees of freedom of light represent different modes, and the potential use of light to create higher dimensional classical entangle states offers a promising potential to drive new technological developments. In this work, we present experimental results demonstrating the orthogonality between transverse orbital angular momentum (t-OAM) of different spatiotemporal topological charges, a previously unverified property of t-OAM. Based on those results, we developed methods to create and characterize a novel family of t-OAM and polarization entangled spatiotemporal structured light. We further provide theoretical analysis to support our study of the entanglement between those modes. By demonstrating the feasibility of leveraging t-OAM as a new family of modes for classical entanglement, our work represents a new advancement towards higher dimensional classical entanglement strategies.

quant-ph↗

arXiv2020

Uncertainty principle for periodic orbital angular momentum and angular position with infinity

The angular uncertainty principle (angular-UP) states the orbital angular momentum (OAM) is precisely defined in an optical vortex with angular position (AP) ranging over 2π azimuthal coordinate (ϕ). However, the pair of observable states is discretely selected and does not correspondent to the pair of unselected linear momentum and position states for the lower bound. This discrete selection is such that the pair of angular uncertainties is independent of n-fold symmetry. Herein, we demonstrate the smaller difference between mean OAM and the product of azimuthal phase-gradient (PG) and h/2π, the larger ϕ range of one periodic helical wavefront in a set of numerous singular light beams, each of which utilizes the superposition comprising two fractional OAM light beams that have a difference of δ in the azimuthal PG. This is a periodically angular UP (periodic-UP) for any pair of unselected states of periodic OAM and AP by a constant product 0.187 h/2π on their underlying uncertainties, or the pair of unlimited scale of periodic OAM and AP uncertainties. This constant lower bound corresponds to the Robeson bound held by linear UP for the pair of unselected observables; however, it is stronger by 2.67 times. We demonstrate a macroscopic example of the periodic-UP by illustrating a physical interpretation of the image constructed by phase shift. Moreover, we demonstrate that the pair of periodically angular uncertainties in this singular light beam is compatible with the pair of angular uncertainties by dividing and multiplying a sub-n periodic number, respectively. We demonstrate that both OAM and AP uncertainties are two monotonic functions of δ and two various distribution types of OAM spectrum and image intensity in this singular light with identically equivalent PGs. We experimentally generate these singular light beams.

physics.optics↗

arXiv2020

A dimensionality and purity measure for high-dimensional entangled states

High-dimensional entangled states are promising candidates for increasing the security and encoding capacity of quantum systems. While it is possible to witness and set bounds for the entanglement, precisely quantifying the dimensionality and purity in a fast and accurate manner remains an open challenge. Here, we report an approach that simultaneously returns the dimensionality and purity of high-dimensional entangled states by simple projective measurements. We show that the outcome of a conditional measurement returns a visibility that scales monotonically with entanglement dimensionality and purity, allowing for quantitative measurements for general photonic quantum systems. We illustrate our method using transverse spatial modes of photons that carry orbital angular momentum and verify high-dimensional entanglement over a wide range of state purities. Our approach advances the high-dimensional tool box for characterising quantum states by providing a simple and direct dimensionality and purity measure, even for mixed entangled states.

physics.optics↗

arXiv2018

Quantifiable example of complementarity relation between optical orbital angular momentum and angular position

A light beam with phase singularity (PS) characterized with azimuthally symmetric angular positions (APs) can be constructed by the rotationally symmetric superposition of n (n is N) fractional vortex light beams with identical charges. The profile of this light beam deforms after propagation owing to its orbital angular momentum (OAM) noneigenvalue, and the deformation degree can be evaluated by the degree of phase dislocation associated with the PS. The expectation value of the mean deviation of its OAM from its characteristic charge value and the variation of the degree of phase dislocation obey a proportional relation. This light beam offers a quantifiable example of a complementarity relation between the observers of optical OAM and AP, which are the OAM noneigenvalue and intensity AP variation, respectively.

physics.optics↗

arXiv2018

Various angle periods of parabolic coincidence fringes in violation of Bell inequality with high-dimensional two-photon entanglement

Two quantum states of two half-charge optical vortexes with relative azimuthal angle π are orthogonal, by which two half-charge spiral phase plates with intersection angle π can be used to demonstrate a parabolic coincident fringe in the Bell inequality experiment with high-dimensional two-photon orbital angular momentum entanglement and to thereby obtain a strong Bell parameter of 3.2. I theoretically demonstrate various orthogonal relations between two quantum states, each of which is a state with a rotational symmetry superposition made up of n fractional orbital angular momentum states, where n is N. I propose a Bell inequality experiment with two n-section spiral phase plates that have these two quantum states, whereby various angle periods with parabolic coincident fringes 2π/n and Bell's parameter 3.2 in each period can be obtained.

quant-ph↗